Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757367AbYH1ANV (ORCPT ); Wed, 27 Aug 2008 20:13:21 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1756872AbYH1ANE (ORCPT ); Wed, 27 Aug 2008 20:13:04 -0400 Received: from 181-30.bbned.dsl.internl.net ([82.215.30.181]:56066 "HELO hubble.stokkie.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1754019AbYH1ANB (ORCPT ); Wed, 27 Aug 2008 20:13:01 -0400 X-Greylist: delayed 396 seconds by postgrey-1.27 at vger.kernel.org; Wed, 27 Aug 2008 20:13:01 EDT Date: Thu, 28 Aug 2008 02:06:19 +0200 (CEST) From: "Robert M. Stockmann" To: linux-kernel@vger.kernel.org Subject: libata, Sound on same IRQ : flaky sound Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII X-AntiVirus: scanned for viruses by AMaViS 0.2.4 (ftp://crashrecovery.org/pub/linux/amavis/) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3085 Lines: 86 Hi, I have a couple of AMD64 machines with onboard sound devices running and they all have one thing in common : flaky sound when one is doing some heavy disk I/O on the SATA disks. Interesting enough /proc/interrupts shows that libata is using the same IRQ as the sound devices : model name : AMD Athlon(tm) 64 X2 Dual Core Processor 6000+ stepping : 3 cpu MHz : 3014.679 cache size : 1024 KB # cat /proc/interrupts CPU0 CPU1 0: 55869 154467838 IO-APIC-edge timer 8: 0 0 IO-APIC-edge rtc 9: 0 0 IO-APIC-level acpi 16: 1453 499686 IO-APIC-level libata, NVidia CK8S 17: 0 0 IO-APIC-level ehci_hcd:usb1 18: 27633 69978987 IO-APIC-level eth0 NMI: 10718 12112 LOC: 154533874 154533852 ERR: 0 MIS: 0 model name : AMD Opteron(tm) Processor 246 stepping : 10 cpu MHz : 1991.355 cache size : 1024 KB # cat /proc/interrupts CPU0 CPU1 0: 18108 19856365 IO-APIC-edge timer 1: 16 7915 IO-APIC-edge i8042 3: 0 56 IO-APIC-edge serial 4: 0 56 IO-APIC-edge serial 8: 0 0 IO-APIC-edge rtc 9: 0 0 IO-APIC-level acpi 12: 346 62269 IO-APIC-edge i8042 14: 0 190 IO-APIC-edge ide0 15: 1 189 IO-APIC-edge ide1 16: 827 358917 IO-APIC-level libata, AMD AMD8111 17: 0 18 IO-APIC-level ohci_hcd:usb1, ohci_hcd:usb2 18: 555 231470 IO-APIC-level HiSax, nvidia 19: 15179 3489796 IO-APIC-level eth0 NMI: 211 511 LOC: 19871720 19871628 ERR: 0 MIS: 0 Kernel is 2.6.15, Preemption Model is (Preemptible Kernel (Low-Latency Desktop)), Memory model is (Flat Memory), [*] Preempt The Big Kernel Lock is switched on. Timer frequency is (1000 HZ) or (100 HZ), but changing this value is of no influence. One of the machines is a genuine dual Opteron machine but i'm rather disappointed with the NUMA capabilities of the 2.6.15 kernel. It does do NUMA, but thats all it does, it doesn't add anything compared to a SMP kernel with NUMA switched off. Does one really need the PREEMPT_RT approach to get rock solid sound as described here ? : "A realtime preemption overview" by Paul McKenney, August 10, 2005 http://lwn.net/Articles/146861/ How about giving your sound device a proper seperate IRQ number? At least libata should like eth0 have its own kernel resources. Regards, Robert PS. please also cc: to my email address. -- Robert M. Stockmann - RHCE Network Engineer - UNIX/Linux Specialist crashrecovery.org stock@stokkie.net -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/